1. Field of the Invention
This invention relates to a pickup apparatus of a structure in which momentary exposure is repeated intermittently, and is particularly suitable for a television camera which effects high-speed image pickup.
2. Description of the Prior Art
Means for photographing an object moving at a high speed and slowly reproducing it is generally known as high-speed photography. In a camera used for this, i.e., a so-called high-speed camera, the object moving at a high speed must be momentarily exposed and photographed with the movement thereof being stopped.
Therefore, a high-speed camera has a mechanism for rotating a rotary shutter having a light-transmitting portion and causing the light beam of a lens to be transmitted therethrough for a very short time.
In a high-speed camera of this type, there is known a method as shown in FIG. 1A of the accompanying drawings wherein a shutter 2 (FIG. 1B of the accompanying drawings) having a sector opening is rotated in front of a lens system 1, or a method as shown in FIG. 2 of the accompanying drawings wherein a rotary shutter 2 is placed immediately in front of a pickup tube 4.
In the first-named method, the spatial limitation for disposing the shutter is loose, but where the light beam entering the lens is thick, it is necessary to make the diameter of the rotary shutter great and particularly, where a zoom lens is used, the light becomes thick at the telephoto end to such a degree that the diameter thereof is substantially equal to the diameter of the lens and therefore, the diameter of the rotary shutter becomes very great, and this leads to the problems in the power of the power source and the operability.
In the second-named method, the imaging plane is relatively small and therefore, the diameter of the rotary shutter can be made small, but great re-formation of the camera containing the shutter therein becomes necessary. Particularly, in a color TV camera, there are three imaging planes for effecting three-color resolution and therefore, it is very difficult to place the shutter on the imaging plane.